Ceramic bodies in the form of tiles are widely used to insulate underlying structures against the high temperatures encountered in certain aerodynamic applications. As an example, an aerodynamic vehicle such as a space shuttle or a supersonic aircraft is heated by friction to a high temperature as it flies through the air. The temperature may be greater than the maximum permissible temperature of the basic metallic airframe structure. A ceramic tile attached to the exterior of the airframe structure insulates the airframe against the aerodynamic heating and also protects it against impact.
One known type of ceramic insulation is a porous ceramic made by pressing together fibers of one or more ceramic materials. This fibrous, porous ceramic is resistant to damage from thermal shock and thermal cycling. However, it is relatively soft and can be damaged by external impact and wear forces. To lessen such damage, it is known to apply protective coatings to the exterior surface of the ceramic insulation, such as those discussed in U.S. Pat. No. 5,079,082.
The protective coatings are quite effective in reducing the incidence of damage to the ceramic tiles from small objects such as dust particles and raindrops. However, even the best protective coatings cannot prevent damage to the tiles from relatively large objects such as rocks, hailstones, and the like. The impact of such large objects can dislodge pieces of the tiles leaving gouges and pits in the tiles, or even holes entirely through the tiles. Any significant damage of this type which reduces the thickness of ceramic protection overlying the metallic airframe and alters the airflow past the tile, can lead to hot spots in the airframe and failures of the entire damaged tiles.
The conventional method of repairing these ceramic tiles has been to remove and replace the damaged tiles. While effectively practiced at a central maintenance base, this approach is inconvenient for field service at a remote location where tiles of different types are not stored and maintained. Therefore, there is a need for an improved approach for replacing damaged porous ceramic tiles and restoring vehicles to operating conditions. The present invention fulfills this need and further provides related advantages.